Objective: To examine the clinical significance of an opioid, tapentadol, for cancer pain relief including its analgesic effects and indications based on our clinical experience. Methods: We retrospectively studied 31 patients receiving tapentadol in our hospital. Results: In 19 successfully treated patients, the numerical rating scale (NRS) scores showed a significant decrease in pain, and the doses at the start and completion of administration were 73.7±25.6 mg (morphine equivalent dose: 30 mg or less) and 125±49.3 mg, respectively. Six successfully treated patients showed improvement of gastrointestinal symptoms. The results of the comparison between successfully and unsuccessfully treated patients suggested titration to be difficult in patients with mixture of somatic pain and neuropathic pain. Conclusion: Based on our clinical experience, we consider tapentadol to be easy to use during the introductory period after treatment with non-opioids or low-dose opioids.

Introduction: The opioid-to-methadone conversion ratio is not constant. Thus, exacerbation of pain associated with switching of these drugs is a concern. We report two cases in which methadone was introduced in combination with epidural block. Case 1: The patient was a 55-year-old man who complained of perineal pain due to recurrent colorectal cancer. Diagnostic imaging could not be performed because of severe persistent pain and breakthrough pain even under treatment with oral oxycodone 600 mg/day. Methadone administration (starting dose, 45 mg/day) was started in combination with continuous lumbar epidural block. The persistent pain mostly dissipated after an approximately 2-week treatment period with methadone 75 mg/day, making magnetic resonance imaging measurement possible. Case 2: The patient was a 62-year-old man who complained of pain in both lower limbs due to spinal metastasis of prostate cancer. Pain impairing body movement persisted even during treatment with oral oxycodone 300 mg/day. The pain was reduced by combination treatment with continuous lumbar epidural block and methadone (starting dose, 30 mg/day), making it possible to perform radiotherapy. At the time of discharge from the hospital while being treated with methadone 45 mg/day, the patient complained minimally of pain. Conclusion: Owing to epidural block, switching to methadone was achieved smoothly without exacerbation of pain.